The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
In a turbojet engine nacelle including a cowl with two halves, each half of the structure and the cowl is hinged on an axis which, when the turbojet engine is set up on the aircraft, is in a substantially horizontal position, aligned on the central axis of the turbojet engine, and in the upper part of the nacelle which surrounds the turbojet engine. In this position, the hinge line of the two halves of the cowl and the hinge line of the two halves of the service structure are in a so-called 12 o'clock position, whereas, when the different halves are closed because the turbojet engine is operational, they are contiguous by their respective facing edges which are then in a 6 o'clock position.
It is known to have a lock secured to the two halves of the service structure. The lock cooperates with the two facing edges of the two annular halves of the service structure in such a manner as to secure them together. Such a disposition is for example known from document FR 2 761 734. Reference will be made thereto for a description of the turbojet engine nacelle. This document describes a lock for securing the two annular halves of the service structure different from that concerned by the present disclosure.
In another state of the technique, the lock is mainly composed of a strike mounted on the edge of a first half of the service structure and a moveable bolt secured to the second half of the service structure, the moveable bolt being rotationally driven on an axis secured to the second half. As it will be displayed on FIGS. 1 to 4, on an axis secured to the second annular half of the service structure, a stick or lever carries the bolt and is operated by the maintenance operator prior to opening the service structure and prior to closing the cowl the other way around. Thus, as it will be displayed on FIGS. 1 to 4, the maintenance operator has already opened the turbojet engine nacelle, separated the two halves of the cowl by making them revolve around their hinge line in a 12 o'clock position, then the two halves of the service structure around their own hinge line in the 12 o'clock position. The maintenance operator then performs the actual maintenance operations of the turbojet engine. At the end of the latter, the maintenance operator brings the free edges of the two-halves of the service structure closer and, at their contact, handles the stick or lever on which the moveable bolt is mounted in such a manner that the bolt penetrates into the strike. The lock is in the closed state. However, to make the closing of the two halves safe, the bolt is mounted on a cam system which are profiled in such a manner as to carry out at the end of the pivoting of the stick or lever a bolting of the bolt in the strike.
The issue becomes apparent when the operator does not entirely push back the stick or lever, or even worse, if he/she ends the rotation of the stick or lever with the aid of the edge of the half-cowl when he/she is closing the latter. The nacelle may hence be considered as closed and the closing bolted while this is not the case. However, a later visual inspection reveals nothing abnormal as the lock and stick or lever thereof are masked by the closed cowl.
There is hence a serious risk for the turbojet engine.